This invention relates to segmented pipe couplings for use in securably connecting the ends of pipes, and in particular preventing the inadvertent mixing of near, but different, sized individual arcuate coupling segments in an assembly about the juxtaposed ends of the pipes that are to be connected.
Segmented couplings for pipes are well known in the art, and comprise two or more coupling segments each having a recess for the reception of a sealing gasket adapted to extend over the adjacent ends of a pair of pipes, and which are to be compressed by the coupling segments into sealing relation with the external peripheries of the respective pipes.
Each such coupling segment intended to couple the ends of grooved pipe has radially inwardly extending keys at its opposite axial sides, the keys being for reception in grooves in the respective pipe ends to perform the required mechanical interconnection between the pipes.
The coupling segments are drawn towards each other by traction bolts which extend through radially outwardly extending bolting pads at the respective opposite ends of the coupling segments. In this manner, the end faces of the coupling segments are drawn towards each other for them to clamp onto each other in the case of a xe2x80x9cflexiblexe2x80x9d coupling, or, for the coupling segments to clamp directly onto the pipe exterior in the case of a xe2x80x9crigidxe2x80x9d coupling. A xe2x80x9cflexiblexe2x80x9d coupling is well known as one which will permit relative movement of the pipes to limited extents and the angling of the axis of one of the pipes relative to the other, whereas a xe2x80x9crigidxe2x80x9d coupling is one which will immobilize the pipes against any such movements. Typical of such flexible couplings are those shown in U.S. Pat. No. 3,189,969 assigned to the assignee of the present application whose teachings are incorporated by reference herein, as well as the styles 75, 77, 72, and 750 couplings available from Victaulic Company of America, Easton, Pennsylvania. Similarly, typical of such rigid couplings are those shown in U.S. Pat. No. 4,639,020, assigned to the assignee of the present invention whose teachings are incorporated by reference therein, as well as the style 07 and 005 couplings available from the Victaulic Company of America.
Segmented pipe couplings are also known for the connection to pipes which do not contain a groove at their connection locations. Such commercially available couplings include: the style 90 and 99 plain pipe end coupling; and style 920 and 929 mechanical T couplings; all available from the Victaulic Company of America.
The aforementioned segmented pipe couplings are commercially available in a successive series of seriatim increasingly sized couplings, which are naturally configured to mate with similarly increased sized pipes.
Through inadvertence it is quite possible for a workman to incorrectly receive and connect two different sized arcuate coupling segments which are relatively close in size to each other. As the incorrectly matched coupling segments are tightened about the pipe end, as by tightening their traction bolts, they will not quite match up and form a circle about their inner diameter, against the exterior, and, in the case of a grooved type coupling, within the peripheral groove of the outer circumference of the pipe ends. Further the outboard corners or surfaces of the improperly mismatched segments of different sizes will not line up evenly. This misalignment, in relatively close size coupling segments (e.g., in the order between one-sixteenth to one-quarter of an inch of each other) is oftentimes difficult to readily visually perceive. Thus the worker may in such situations mismatch the individual coupling segments connected about the pipes being connected thereby, without readily realizing that a mismatch has occurred. This results in less than optimum sealing engagement between the pipe ends. Accordingly it is desirable to prevent such an inadvertent mismatch of the individual coupling segments, while providing a segmented pipe coupling having all the other advantages of presently available segmented pipe couplings, such as typically shown in aforementioned U.S. Pat. Nos. 3,189,969 and 4,639,020 and available from Victaulic commercial styles 75, 77, 07, 005, 90, 99, 72, 750, 920, or 929. Further it is desirable to prevent such an inadvertent mismatch by a simple modification of the presently existing coupling segments, which can be accomplished in a low cost manner, and will provide the workman with a readily visual indication that a mismatch is being attempted between closely sized coupling segments.
The present invention illustratively shown in conjunction with grooved end pipe couplings provides a series of successively sized segmented pipe couplings each of which is adapted to securably connect similarly configured and sized pipe ends of juxtaposed pipes. Each of the series of segmented pipe couplings comprises two or more arcuate coupling segments, with the number of arcuate segments being determined by the size of the pipe. The segmented pipe couplings are intended to be assembled in arcuate end-to-end relationships for encircling the juxtaposed ends of the pipe to be coupled. Each of the coupling segments includes radially inwardly extending and axially spaced keys which are intended to cooperatively engage peripheral grooves about the outer circumference of the juxtaposed pipe ends being connected thereby. Bolt receiving pads are provided at the ends of each of the coupling segments for receiving bolts, with the tightening of the bolts bringing the bolt pads together to urge the individual coupling segments radially inwardly. This produces a reduction in their internal circumference and causes clamping engagement with the pipe exterior, with the keys of the coupling segments being tightly retained within their respective pipe recesses when the bolts are in their fully tightened condition. In order to prevent a mismatch of different size coupling housings which are relatively close in size, an anti-mismatch means is now provided on individual ones of the arcuate coupling segments for preventing the fully bolt tightened connection of near sized coupling segments. The anti-mismatch means will create an interference relationship which, in addition to preventing the fully bolt tightened connection of the size mismatched coupling segments to each other, gives a readily discernible visual indication to the workman that an attempt is being made to inadvertently connect two differently sized coupling segments.
When two arcuate coupling segments of the same size are brought together in an end-to-end relationship, the ends of the arcuate segments are configured to nest together in close proximity, such that the tightening of their bolts permits the coupling segments to closely encircle the outer periphery of the pipe. However, according to the present invention the ends of a near size arcuate coupling segment are modified such that if an attempt is made to couple two different, but closely sized, arcuate segments together, their ends will abut. This will prevent the desired nesting relationship necessary to properly encircle the pipe ends being connected. This non-nested, or abutting anti-mismatch, relationship between successively sized coupling segments, is provided by including a first member on one of the coupling segments and a second member on the other of the coupling segments. The first and second members of the same size coupling segments will appropriately nest together. However, the orientation of the first and second members on a near-size arcuate coupling segment differs, such that they will abut if improperly mixed with the other sized arcuate coupling segment. This provides an interference relationship, opposing the bolted to connection of two successively, but differently, sized coupling segments. This interference relationship advantageously provides a separation gap between the bolt pads of the differently sized coupling segments so as to provide a visual indication that the workman is attempting to connect two differently sized arcuate coupling segments.
In accordance with one embodiment of the present invention which is a modification of the rigid grooved coupling segments shown in aforementioned U.S. Pat. No. 4,639,020, each of the ends of the arcuate coupling segment includes an inclined face. The angular direction of the inclined end faces of the same sized coupling segments correspond. Thus, in the well known manner, as two such symmetric arcuate coupling segments are bolt tightened, the nested interengagement of their inclined end faces produces self-adjustment of the coupling segments and a rigid coupling of the pipe ends. In accordance with the present invention the angular direction of the inclined end faces of the next size coupling segment is reversed. Thus while two such reversed angle coupling segments will mate with each other, if an attempt is made to couple one such reverse angled coupling segment with the smaller, non-altered, coupling segment, the inclined end faces will abut in an interference, non-nested relationship. Hence the improvement of the present invention may be incorporated in the rigid type couplings shown in aforementioned U.S. Pat. No. 4,639,020, by merely reversing the angle of the inclined end faces in alternate, successively sized coupling segments. Alternatively, the slope angle could be modified in the alternate ones of successively sized coupling segments.
Other embodiments are disclosed as a modification of the flexible groove couplings of the type shown in aforementioned U.S. Pat. No. 3,189,969. The end faces of such previously available arcuate coupling segments have been flat. When two such different size coupling segments have inadvertently been brought together, the out of round inner diameter formed thereby, which will be against the outer periphery of the pipes being joined, may not be readily discernible to the workman. To prevent this from happening, in accordance with the present invention the previously flat end faces of the next size coupling segments now include cooperating projections and recesses. When two such coupling segments of the same size are brought together their projections and recesses will mate in nesting relationship. However, should an attempt be made to connect one such coupling segment to a coupling segment having a flat end surface, the abutment of the projection against the flat end surface of the other coupling segment will provide an interference. This serves as an anti-mismatch means to readily advise the workman that an attempt is being made to connect two differently sized flexible groove coupling members.
As a further modification of the present invention intended for use in conjunction with flexible groove couplings, none of the coupling segments will have a flat end face. Each of the coupling segments will include a projection and cooperating recess. However, the orientation of the projection and cooperating recess on the next size coupling segment will be reversed. Thus should two of the same size coupling segments be brought together, their respective projections and recesses will mate in a nested relationship. However should an attempt be made to connect one such coupling segment with the next size coupling segment, their projection will abut, thereby preventing the nested interengagement therebetween. Such abutment will again provide a readily visually discernible indication to inform the workman that an attempt is being made to connect two differently sized coupling segments. Alternatively, instead of reversing the location of the projections and recesses in alternate sized couplings, their shape could be changed.
It is therefore seen that a primary object of the present invention is to provide an anti-mismatch means to prevent the connection of two different, but closely, sized arcuate coupling segments about juxtaposed pipe ends.
A further object of the present invention is to provide such arcuate coupling segments in which the anti-mismatch means is provided by a simple modification of presently available commercial arcuate coupling segments.
Yet another object of the present invention is to provide such arcuate coupling segments in which the anti-mismatch means is provided by reversing the orientation of the surfaces at the end-to-end connection of otherwise symmetrically configured arcuate coupling segments.
Yet another object of the present invention is to provide an anti-mismatch means in conjunction with rigid grooved coupling segments having inclined end faces, in which the angle of inclination is reversed or its slope changed in the alternate ones of a series of successively sized coupling segments.
An additional object of the present invention is to provide such arcuate coupling segments which are of the flexible groove type, in which the end faces of mismatched coupling segments will produce an interference gap.
Yet another object of the present invention is to provide a series of successively sized segmented pipe segments wherein an anti-mismatch means is provided at their end faces to produce a separation gap should an attempt be made to connect two different, but closely, sized arcuate coupling segments.